Estimation of Sorption Coefficient Based on Organic Carbon Content and Soil Texture

Experimental determination of sorption behaviour is a key parameter for modelling the distribution and transport of contaminants in soil, serving as a foundation for environmental risk assessment and remediation planning. Conventional approaches based solely on the content of the soil organic matter do not provide representative results for organic-poor soils (organic carbon content ≤ 1%, w/w). This study verifies multivariate regression models for estimating the distribution coefficient Kd, incorporating both organic carbon content and grain size characteristics, namely the proportion of clay (< 0.002 mm) and sand (> 0.063 mm) particles. Building on previous work that identified three distinct soil groups based on textural and sorption characteristics, this study extends the dataset with 19 additional samples from organic-poor soils collected across nine locations in the Czech Republic. The results confirm that integrating grain size parameters significantly enhances the predictive accuracy of Kd and improves the possibilities of assessing the fate of contaminants in the environment.